Railway car journal box seals and the like



y 1967 R. L. OLSON RAILWAY CAR JOURNAL BOX SEALS AND THE LIKE Filed Aug.13, 1963 INVENTOR. 6/ c6 ar 0 1. 0/6017 I Y )/W ISb' ATT RNEYS UnitedStates Patent 3,319,969 RAILWAY CAR JOURNAL BOX SEALS AND THE LIKERichard L. Olson, Chicago, Ill., assignor to Dilre-O-Seal Incorporated,Chicago, 11]., a corporation of Illinois Filed Aug. 13, 1963, Ser. No.301,749 2 Claims. (Cl. 277-130) This invention pertains to seals forrot-ary shafts and more particularly relates to seals which areespecially suitable for railway car axle journal boxes of the typeconforming to standards of the Association of American Railroads. Suchjournal boxes are commonly equipped with an upright pocket at theirinner ends for receiving an oil and dust seal.

Many and various oil and dust seal constructions have been proposed forrailway car journal boxes. A general characteristic of prior such sealshas been complex assemblies of parts, special relationships of materialsand in most instances involving rigid components as well as yieldablecomponents. With all their complexities and special forms andrelationships of parts, prior journal box seals have, in addition tohigh cost for at least the more efiicient seals, all been unduly shortlived, subject to wear and thus leakage in relatively short time inservice, and most troublesome of all, have been unduly liable todestructive damage due to the often violent gyrations, oscillations andreciprocations of the journal relative to the journal box in running ofthe associated car.

Accordingly, it is an important object of the present invention toprovide a substantially improved relatively low cost, simple and highlyefficient journal box seal which overcomes the various deficiencies ofprior journal box seals.

Another object of the invention is to provide a new and improved journaland like seal which is constructed entirely from cellular elastomericmaterial.

A further object of the invention is to provide a new and improved sealfor railway car journal boxes which will retain its sealing relation tothe journal in an unusually efiicient manner in spite of variousgyratory, oscillatory and reciprocatory relative movements of thejournal relative to the journal box.

Still another object of the invention is to provide a new and improvedmonolithic journal box seal which is efficiently self-centering in thejournal box seal pocket.

A yet further object of the invention is to provide a new and improvedseal for journals and shafts which is self-lubricating.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of a preferredexemplary embodiment thereof, taken in conjunction with the accompanyingdrawing, in which:

FIGURE 1 is a fragmentary longitudinal sectional elevational detail viewthrough a railway car journal box showing a seal according to thepresent invention in place in the seal pocket;

FIGURE 2 is a sectional elevational detail view taken substantially onthe line 11-11 of FIGURE 1; and

FIGURE 3 is an enlarged fragmentary sectional detail view through thejournal engaging inner margin of the seal member.

Referring to FIGURE 1, a railway car journal box 5 provides therein theusual oil chamber 7 receptive of saturated wicking, waste and the like,as is customary. At its front or outer end the journal box has the usualopening adapted to be closed by a door (not shown). Extending through anopening 8 in a double inner or rear wall 9 of the journal box definingan upwardly opening seal pocket 10 is a journal portion 11 joined by alarger diameter dry seat portion 12 to an axle 13 carrying adjacent tothe seat a wheel 14. At its front end the journal portion 11 has aflange collar 15 between which and the fillet shoulder adjacent the dryseat -a bearing 17 is en gaged and supports a wedge 18 on which ismounted a top wall 19 of the journal box.

According to the present invention, a new and improved seal 20 isprovided which is dimensioned to fit within the seal pocket 10 and aboutthe dry seat 12 to prevent leakage of oil from the oil chamber 7 throughthe necessarily substantially oversize journal clearance opening 8, andto prevent dust and dirt from entering into the journal box through suchopening. This seal 29 is desirably constructed as a unitary member ofelastomeric, compressible construction, and more particularly of asuitable elastomeric plastic material comprising a body at least a majorproportion of which has therein and especially in the journal engagingportions thereof small, discrete, predominantly closed, bubble-like gasfilled cells whereby the material is bulk compressible as distinguishedfrom merely fiowably deflectable as would be true of the elastomer as asolid mass free from the cellular structure. While a solid elastomer isdeflectable, any deflections thereof are without change in volume. Onthe other hand, what may be termed as the essentially bubble filledelastomer of the seal 20 is bulk compressible, that is substantiallyreducible in volume under compression. This affords numerous salientadvantages in a seal structure. Thus, the seal member 20 can bedimensioned to fill substantially entirely the containing space, insubstantially confined relation, between the parallel walls defining theseal pocket 16, without need for expansion space as would be necessarywith a solid, that is incompressible, elastomer seal in order to avoidbinding, chafing, overheating, bursting, etc. to which solid elastomersunder confinement are subject. Further, for the same size, the cellularelastomen'c seal 20 is substantially lighter in weight and requiressubstantially less material than if it were made of solid elastomer.Because of its inherent bulk compressibility, the cellular seal member20 is capable of making closely conforming contact with opposingsurfaces without undue pressures, tensions or stresses, whereby wear ofthe seal surfaces and the opposed engaged surfaces is substantiallyminimized. In fact, test of the cellular elastomer seal in thelaboratories of the Association of American Railroads beyond the pointof destruction of prior seals has failed to break down the cellularelastomer seal, and as is well known such tests subject the seal togreater punishment than anticipated under the most arduous runningconditions.

Although the seal member 20 may be constructed with a substantiallyuniform fine discrete closed cell structure, it may be advantageouslymade of a partially open or interconnected cellular and combined closedcell in ternal structure. Among suitable oil resistant materials arepolyurethane and synthetic rubbers. Among synthetic rubbers that aresuitable are those identified by trade names Hycar (B. F. GoodrichCompany) and Paracril (U.S. Rubber Company). Molding and blowing of suchmaterials is known in the art. For synthetic rubber, formulations mayinclude a suitable quantity of the rubber, a plasticizer, a vulcanizingagent and a gas liberating agent capable upon the application of heat ofliberating substantial quantities of gas and thereby swelling orexpanding the elastomeric composition. For a more detailed descriptionof certain exemplary compositions and methods of molding reference maybe had to my Patent No. 2,815,549 issued Dec. 10, 1957. While in thatpatent a method particularly adapted for main taining the molded memberfixed in one side of a mold and releasable from the opposite side of themold is dis- 6 closed, in the present instance, of course, molding mustbe effected in such manner as to have the seal member releasableentirely from both sides of the mold.

As best seen in FIGURES l and 2, the seal member 29, in this instance,is shaped substantially complementary to the seal pocket 1! of thejournal box. Hence, the seal member 20 has opposite vertical parallelside edges 21, a generally semi-cylindrical bottom or lower edge 22 anda top edge 23. 'Both of the side edges 21 and the lower edge 22 arearranged by dimensioning of the width and height of the seal member tobe in sufiicient clearance relation to the opposing wall surfaces withinthe pocket when the seal member is engaged about the dry seat 12 by acircular sealing edge 24 defining an opening through the seal member forthis purpose. Through this arrangement, at least a limited practicalrange of sideward and downward movement of the seal member with theengaged journal in its operating gyrations relaitve to the journal boxis permitted without placing any substantial compressive pressure on theseal member in its plane.

In order to resist rocking, turning movements of the seal member 20about the axis of the journal, and excessive downward movement, suitableintegral, preferably tapered, centering pads 25 are provided on theedges 21 and similar pads 26 on the edge 22, at spaced intervals. Thepads 25 project from desirably the upper and lower end portions of therespective sides 21 into engagement with the opposing side wallsdefining the pocket 10. Similarly the pads 26 engage the bottom walldefining the pocket 10. All of these pads are compressibly displaceableinto themselves or into the body of the seal member 20 or a combinationof such compression into themselves and into the seal body. Ifpreferred, the pads may be constructed as denser projections from thebody of the seal member 20, or they may be constructed as more readilycompressible and less dense projections, although for most purposes itwill be sufiicient to have the density of the material in the padprojections 25 and 26 substantially the same as the density of theremainder of the body of the seal member, and more particularly thatportion of the body of the seal member contiguous to the pads.

By virtue of their relatively small dimensions compared to seal edgearea and their compressibly displaceable relation with respect to thebody of the seal member 20, the pads 25 and 26 Will afford compressionrelief in the planar movements of the seal member 20 with the journal11. This avoids such distortions in the seal member as might causepulling of the journal-engaging internal annular sealing bearing edge 24of the seal member away from the journal into leakage gap at theopposite side from that against which excessive compression force may beexperienced during violent sideward and downward relative displacementsof the journal and journal box in running operation, especially afterthe bearing portion of the journal and the bearing 17 have become worn.

For efiicient sliding, sealing engagement with the front and rear wallsurfaces defining the journal box pocket 10, the seal member 20 is of athickness complementary to the spacing of said walls. Such sealingengagement is effected in substantial depth outwardly relative to theedge defining the opening 8 both vertically and sideward- 1y. Moreover,by virtue of substantially complementary filling of the space betweenthe upper portions of the parallel front and rear wall surfaces definingthe pocket 10, the upper marginal portion of the seal member 20 and itsupper edge 23 provide an effective top closure for the seal pocket 10.In this respect, the upper of the side edge pads 25 are desirablyaligned with the upper edge 23 to complement the closure function of theupper margin of the seal member.

Desirably, at least the broad, parallel opposite faces of the sealmember 20 are provided with an at least substantially impervious skin 27(FIG. 3) to prevent leakage through the body of the seal member of oilfrom within the oil chamber 7 of the journal box, and also to preventclogging of the material of the seal body with dust and dirt where asubstantial proportion of the body is open cell structure. Of course, ina substantially entirely closed cell structure of the seal body the skin27 need be no more than cell wall thickness of the closed cells definingsuch surfiaces of the seal member.

For improving sealing engagement of the inner journal-engaging edge 24with the dry seat portion 12, such edge 24- is desirably formed on adiameter at least slightly smaller than the diameter of the journal seatportion 12. Because the cellular elastomeric material is bulkcompressible, it readily expands about the engaged portion of thejournal seat 12 without strain or stress and by virtue of the at leastsubstantial proportion of closed cells in the material is highlyresistant to tearing under the stretching tension adjacent the surfaceof the edge 24. Moreover, by reason of the bulk compression afforded bythe closed cell structure, excellent sealing pressure uniformly aboutthe entire annulus of the sealing edge 24 against the dry seat 12 isattained not only due to contraction of the elastic material but alsodue to the desirable increasing spring rate developed by compression ofthe closed gas cells in the compressed portion of the material.

Increased flexibility in the journal engaging edge 24, and thus improvedfollowing of the sealing edge portion of the seal member of anygyratory, eccentric, oscillatory movements of the journal relative tothe journal box, without development of gap between any portion of thesealing edge 24 and the journal, is attained by having the edge 24 on aridge or rib 28 of reduced thickness as compared to the principalthickness of the seal member 20, as best seen in FIGS. 1 and 3. Toimplement the bulk compressibility of the sealing ege area of thesealing rib 28 and to gain the advantage of flexibility both radiallyand axially relative to the journal opening in the seal member, one orboth sides, and in this instance both sides 29 of the sealing ribprojection 28 are of a concavely curved form, whereby the rib isnarrowest adjacent the surface 24 and is progressively thicker towardits integral base juncture with the body of the steel member 20.Further, to relieve bending stresses, juncture of the surfaces 29 withthe sides 27 of the seal member is preferably on a reverse, convexcurvature 30 thus aflFording a substantially ogee curvature along thesides of the rib 28 with the major extent of the curvature comprisingthe inward, generally concave curvature 29.

Flexibility of the sealing rib 28 and its side contours afiord advantagealso in facilitating assembly of the journal through the journal openingin the seal member, by easing of the sealing rib 28 over and past thecollar flange 15 of the journal and then onto the dry seat portion 12 ofthe journal. Furthermore, in axial movements of the journal relative tothe journal box and thus of the seal member 20 which is held in thejournal box against any substantial movement axially with the journal,the axial resilient flexibility of the rib 28 as well as its range ofresilient radial flexibility enables the sealing rib to maintaineflicient sealing engagement with the journal. Further, during unusualrelative axial movements of the journal effecting shift of the-dry seat12 inwardly or outwardly relative to the journal box 5 to the extentthat the sealing rib 28 may come into proximity or engagement with thefillet shoulders at the opposite ends of the dry seat, the flexibilityof the rib 28 and its curved contoured sides assures not only thatsealing engagement will be maintained with the journal but that the ribwill suffer no damage from movement against the fillet shoulders andwill permit movement of the jourrial surface therethrough withoutseizing or doubling over or other deleterious reaction.

Although the size of individual, unconnected gas cells in the sealingrib 28 may be substantially the same as to size and distribution as theremainder of the internal structure of the seal member 20, for greaterresilient flexibility air cells or bubbles 31 of larger diameters may beinterspersed with or substantially uniformly developed in the sea-lingrib 28 and more particularly in the narrower crown area thereof. Theremay be a gradual transition of bubble size from the smaller bubblesinteriorly of the main body of the seal member outwardly toward thesealing edge surface 24, or a more or less abrupt transition from thesmaller to the larger bubbles, if preferred. An advantage of havinglarger size bubbles in the narrower more flexible portion of the sealingrib 28 as compared to the bubble size interiorly therefrom in the sealmember 20 resides in that the spring rate of smaller bubbles issubstantially higher, substantially progressively according todiminishing size, than the spring rate of larger size bubble cells.Accordingly, the multiplicity of the large gas filled bubble cells inthe crown area portion of the sealing rib 28 afford :a desirable lowspring rate which will easily accommodate and absorb the virtuallycontinuous vibratory movements of the engaged journal in running withouttending to similarly vibrate the entire :body of the seal ring diskmember 20, enabling it to maintain a reasonably snug though slidablesealing contact with the opposing fiat parallel wall surfaces definingthe journal box seal pocket 10. The sealing rib 28 may therefore beconsidered a vibration damping, shock absorbing annular area or portionof the sealing member 20.

To minimize frictional resistance and wear between the sealing edgesurface 24 of the seal member and the socalled dry seat portion 12 ofthe journal, in spite of the fairly snug elastically gripping engagementof the sealing edge 24 with the journal surface and the generallyrelatively high coeflicient of friction of the elastomeric material, theconstruction and arrangement of the sealing edge 24 is desirablyself-lubricating. Although from the very purpose of the seal to retainoil within the bearing and lubricating chamber 7 of the journal box, thedry seat name by which the journal portion 12 is known is indica tive ofthe fact that it may run dry and at least run with a low order oflubrication. Accordingly, the sealing edge surface 24 may be treated toa' suitable depth with a lubricating substance such as graphite,molybdenum disulphide, tungsten powder, platinum, lead, zinc, beads orspheres of silicone, and other materials having low coefficients offriction. On the other hand, a simple and quite effectiveself-lubricating arrangement comprises utilizing at least a portion ofthe area within the sealing rib 28 as an oil reservoir. This may beelfected by impregnating the open cellular structure adjacent thesurface 24 Where at least a proportion of the material is of porous opencellular structure and the surface 24 is free from a skin or has aporous skin. On the other hand, where the internal structure within thesealing rib 28 is substantially entirely closed cell and the sealingsurface 24 is with or without a definite skin, impregnation withlubricant in fluid, semiliquid or particulate form is adapted to beeffected through perforations 32 of any preferred depth extendinginwardly from the surface 24 and through at least some of the bubblecells, such as the cells 31. In FIGURE 3 the perforations 32, forillustrative purposes, are illustrated in highly exaggerated form.Actually, such perforations may be no more than pin pricks sufficient topuncture the superficial surface 24 and underlying bubble cells. Afairly uniform pattern of the perforations 32 throughout the annulus ofthe surface 24 affords best results.

Impregnation of the punctured cells with lubricant may be effected inany suitable manner such as by compressing the crown portion of the sealrib 28 to drive out gas within the punctured bubbles while the rib isimmersed in the lubricating material so that when the compressionpressure is released the lubricant will be sucked into the puncturedvoids afforded by the cells. Probably a more efiicient manner ofeffecting lubricant impregnation rather quickly is by subjecting theperforated rib 28 to a vacuum whereby to withdraw gas from the puncturedcellular structure, and then restoring normal, or even a higheratmospheric pressure while the sealing rib and more particularly thesealing surface 24 is immersed in the lubricant, thus attainingsubstantially uniform impregnation.

For highest efficiency, the perforations 32 are of a depth which extendsinwardly a substantial distance beyond the anticipated compression lineor diameter as indicated by 12 in FIGURE 3 (representing the dry seatsurface 12 of FIGURES 1 and 2) to which the sealing surface 24 willnormally be expanded and thus the contiguous crown area of the rib 28compressed in service. Such compression squeezes some of the lubricantout onto the sealing surface 24 and between the sealing surface and theengaged journal or shaft surface. Then, in the relative radial movementsof the rotary surface and the sealing surface 24 pressure ejection oflubricant from the oil reservoir through the perforations 32 acting asfountain orifices in response to inward pressure brings additionallubricant to the surface. Excess lubricant is sucked back into thereservoir through the orifices 32 which act as suction openings onrelief of pressure and expansion of the sealing rib during theeccentric, vibratory relatively radial movements of the sealing surface24 and the engaged rotary surface. There is thus in running operation alubricant ejection-suction action through the lubrication well porosityafforded within the sealing surface 24, which is highly efficient,especially in respect to the journal seal where there is a more or lesscontinuous generally low order, but at higher speeds higher order ofrelative eccentric movement between the journal and the seal member 20.

Ifdesired, at least some lubrication well orifice perforations 33 may beprovided in the side surfaces 29 of the sealing rib 28 for lubricationwhen such surfaces engage during relative movement with a surface of thejournal.

While a considerable range of proportion of closed cells to the volumeof the body of the seal member 20 may be provided, it should beunderstood that the smaller the bubble-like cells are and the moreuniform their distribution, the stronger will be the resulting structureof the material, and more particularly its tear strength. Excellentresults are attained where the upper limit for the diameters of theeffective preponderance of the hubbles may be on the order of about 0.02to 0.03 inch to thereby benefit by the rapidly increasing resistanceagainst bursting and the flexural strength thus attained. The lower sizelimit, particularly for low percentages of confined gas, is a practicalone, depending on the ability to form interbubble walls ofcorrespondingly reduced thickness with the chosen material and by theparticular expanding, blowing or bubble forming technique employed andmay be on the order of 0.001 inch diameter or some What less for strongmaterial and relatively thick bubble walls. Generally, it is simpler toform the bubbles more or less uniformly throughout the mass, except atthe progressive transition or boundary region as it merges into the skinareas of the member. The particular ranges of sizes need not apply toevery closed cell since a small percentage, such as 10% to 15% or more,may be undesirably too large or too small without adverse affect, aslong as the effective preponderance of the bubbles are in the preferredrange of sizes. Nitrogen filled bubbles are desirable.

As will be observed, the exemplary form of the gen erally slab-like ringdisk journal box seal member 20 is symmetrically formed, especially inrespect to substantially identical opposed axially facing sides, so thatit is readily reversible. This not only simplifies and eXpeditesassembly but enables reversal of the seal member should it be foundduring servicing of the equipment that one side has sustained more wearor has been subjected to some wearing abuse in service. Generally,however, it will be found that unless there has been some unusualmalfunction of the contiguous equipment or a damaged part or surfaceengaging the seal member, little wear will be evident on the axial sidesof the member even after prolonged service, assuming, of course, thatthe proper elastomeric material has been selected for the anticipatedoperating conditions for which the associated equipment is to be used.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention:

1. In a railway car journal box having an opening therethrough aboutwhich is a seal pocket and a rotary journal extending through saidopening into the journal box and subject to relative movements inrespect to said box during rotary operation:

a sealing member substantially complementary to and mounted within saidpocket;

said sealing member'including a body of compressible elastomericmaterial having an opening through which said journal extends anddefined by an annular portion having an edge sealingly gripping saidjournal;

said body having substantially uniformly distributed therethrough smallgas-filled closed bubble-like cells, with the cells in said annularportion being of substantially larger size than the cells in the bodysurrounding said annular portion so that said annular portion is moreflexible than the remainder of the body to permit relative easilyfollowing movement of said annular portion with the journal in saidrelative movements of the journal and relative to said remainder of thebody;

said remainder of the body being of substantially greater thickness thansaid annular portion as well as having smaller cells therein;

said edge being normally cylindrical;

said annular portion having a substantially ogee curvature on its sidesfrom said edge to said remainder of the body;

and perforations extending into and through said edge and through saidsides into some of said larger cells and lubricant being in said largercells into Which said perforations extend.

2. A compressible elastomeric railway car journal box seal comprising aunitary body of generally ring disk slab form adapted to be mountedwithin the usual journal box seal pocket:

said body having a central circular sealing edge defining a journalopening and adapted to engage a journal sealingly;

outer vertical substantially parallel edges and a lower generallysemi-cylindrical edge joining the lower ends of said vertical edges;

said vertical edges and lower edge being adapted to remain normally insubstantially spaced relation to opposing surfaces within the journalbox seal pocket; said vertical edges and said semi-cylindrical edge bothhaving a plurality of spaced projecting spacer andcentering pads whichare short and have substantially longer intervening edge portionstherebetween and are engageable with the respectively opposing surfaceswithin said seal pocket to afford compression relief in the planarmovements of the seal member with the journal whereby to avoidundesirable distortions in the seal member which might cause pulling ofthe journal-engaging sealing edge away from the journal into leakage gapat the opposite side from that against which the excessive compressionforce may be exerted during violent sideward and downward relativedisplacements of the journal and journal box in running operation andespecially after the bearing portion of the journal and possibly thebearing within the journal box have become worn.

References Cited by the Examiner UNITED STATES PATENTS 2,997,755 8/1961Olson.

3,010,741 11/196'1 Hoyer '277-237 3,022,097 2/1962 Seniff et al. 27710 X3,108,813 10/1963 Brown et al. 2771 3,220,786 '11/ 1965 McCutchen 308240FOREIGN PATENTS 1,263,660 5/1961 France.

SAMUEL ROTHBERG, Primary Examiner.

1. IN A RAILWAY CAR JOURNAL BOX HAVING AN OPENING THERETHROUGH ABOUTWHICH IS A SEAL POCKET AND A ROTARY JOURNAL EXTENDING THROUGH SAIDOPENING INTO THE JOURNAL BOX AND SUBJECT TO RELATIVE MOVEMENTS INRESPECT TO SAID BOX DURING ROTARY OPERATION: A SEALING MEMBERSUBSTANTIALLY COMPLEMENTARY TO AND MOUNTED WITHIN SAID POCKET; SAIDSEALING MEMBER INCLUDING A BODY OF COMPRESSIBLE ELASTOMERIC MATERIALHAVING AN OPENING THROUGH WHICH SAID JOURNAL EXTENDS AND DEFINED BY ANANNULAR PORTION HAVING AN EDGE SEALINGLY GRIPPING SAID JOURNAL; SAIDBODY HAVING SUBSTANTIALLY UNIFORMLY DISTRIBUTED THERETHROUGH SMALLGAS-FILLED CLOSED BUBBLE-LIKE CELLS, WITH THE CELLS IN SAID ANNULARPORTION BEING OF SUBSTANTIALLY LARGER SIZE THAN THE CELLS IN THE BODYSURROUNDING SAID ANNULAR PORTION SO THAT SAID ANNULAR PORTION IS MOREFLEXIBLE THAN THE REMAINDER OF THE BODY TO PERMIT RELATIVE EASILYFOLLOWING MOVEMENT OF SAID ANNULAR PORTION WITH THE JOURNAL IN SAIDRELATIVE MOVEMENTS OF THE JOURNAL AND RELATIVE TO SAID REMAINDER OF THEBODY;